Increased NMDA-induced excitability during ethanol withdrawal: a behavioural and histological study

Intrahippocampal injections of N-methyl-D-aspartic acid (NMDA) leads to neurodegeneration in a dose-dependent manner. Chronic administration of ethanol to animals leads to CNS tolerance and dependence. Hyperexcitability following ethanol withdrawal is thought to be related to increased sensitivity of the NMDA receptors. The purpose of this study was to investigate this predisposition to hyperexcitability by intrahippocampal injection of low dose of NMDA. Using control and ethanol-withdrawn male Wistar rats, behavioural indices were determined immediately after injection and morphological damage was assessed after a period of recovery. There was significantly increased hyperactivity in the ethanol-treated rats immediately after injection. Morphological damage resulting from 5 nmol of NMDA was significantly greater in the CA3 region of the hippocampus in these animals. These data support the hypothesis that ethanol dependence and subsequent withdrawal is associated with increased sensitivity to NMDA which may underlie ethanol withdrawal-associated brain damage.

Inactivated hepatitis A vaccine: a safety and immunogenicity study in health professionals

The safety and immunogenicity of an inactivated hepatitis A vaccine (HM175) were evaluated in 151 seronegative health professionals (age range, 21-65 years; mean, 30). A 720-ELISA unit dose was administered to 78 vaccinees at 0, 1, and 6 months and to 73 vaccinees at 0, 1, and 12 months. Seroconversion rates were 90% in both groups 1 month after the first inoculation and 99% and 100%, respectively, 1 month after the second inoculation. Geometric mean antibody titers (GMTs) 1 month after the third inoculation were highest in the group vaccinated at 0, 1, and 12 months. GMTs were higher in women than in men. The vaccine was well tolerated; the most frequent side effect was transient soreness at the site of inoculation. No serious adverse reactions were observed. Thus, HM175 inactivated hepatitis A vaccine is safe and highly immunogenic.

Severity of symptoms in chronically institutionalized geriatric schizophrenic patients

OBJECTIVE

The goal of this study was to characterize the symptoms of geriatric, chronically ill, institutionalized schizophrenic patients and investigate age-related differences in schizophrenic symptoms and cognitive performance from early adulthood to late senescence.

METHOD

The Positive and Negative Syndrome Scale and the Mini-Mental State examination were used to assess the schizophrenic symptoms and cognitive performance, respectively, of 393 institutionalized schizophrenic patients stratified into seven groups designated by 10-year age intervals from 25 years to over 85 years.

RESULTS

In the comparisons of the seven age groups, significant differences between groups in positive and negative subscale scores on the Positive and Negative Syndrome Scale and in Mini-Mental State scores were revealed. Significant correlations between Mini-Mental State scores and Positive and Negative Syndrome Scale negative symptom scores, but not positive symptom scores, were found for all age groups, except for the youngest patients studied. Current treatment with neuroleptics and prior treatment with ECT, insulin coma, or leukotomy could not account for the poor cognitive performance of the older schizophrenic patients.

CONCLUSIONS

The older schizophrenic patients continued to experience psychotic and nonpsychotic symptoms in senescence. Their positive symptoms were moderately less severe and their negative symptoms and cognitive impairment were significantly more severe than those of the younger patients. Somatic treatment appeared not to be responsible for the severe cognitive impairment and negative symptoms of the older patients. These data are relevant to chronically hospitalized geriatric schizophrenic patients but not necessarily to all geriatric schizophrenic patients.

Transverse vaginal septum. A case report

A case occurred of imperforate, complete transverse vaginal septum in the lower third of the vagina. The patient presented at 16 years of age with primary amenorrhea and was found to have hematocolpos. The clinical impression was an imperforate hymen because of the very low position of the septum in the vagina. After excision the diagnosis of transverse vaginal septum was made histologically because of the presence of müllerian duct (mesodermal origin) tissue in the septum. The patient also had syndactyly of the second and third toes on her right foot. The association of these two congenital abnormalities has not been reported previously.

Validity and utility of the ADAS-L for measurement of cognitive and functional impairment in geriatric schizophrenic inpatients

This study examined the usefulness of the Alzheimer's Disease Assessment Scale-Late Version (ADAS-L) for assessing cognitive and behavioral impairment in geriatric schizophrenic patients. Subjects were 339 geriatric schizophrenic inpatients. Discriminant function analyses compared the Mini-Mental State Examination (MMSE) with the ADAS-L as independent variables predicting the level of impairment on the criterion measure, the Clinical Dementia Rating. The ADAS-L surpassed the MMSE at correctly distinguishing severe to profound impairment; the MMSE was superior for identifying absent or questionable impairment. Findings provide evidence for the concurrent validity of the ADAS-L as an instrument for measuring impairment in geriatric schizophrenic inpatients.

Analysis of cybrids harboring MELAS mutations in the mitochondrial tRNA(Leu(UUR)) gene

MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes), a maternally inherited mitochondrial disorder, has been associated with an A-->G transition at nucleotide 3243 and a T-->C transition at nucleotide 3271, both in the mitochondrial tRNA(Leu(UUR)) gene. We transferred mitochondria harboring these mutations into human cells lacking endogenous mtDNA (rho o cells), and analyzed the resulting transmitochondrial cytoplasmic hybrid (cybrid) cell lines for the relationship of genotype to phenotype. Cybrids containing high levels of mutated genomes showed decreased rates of synthesis of mitochondrial translation products, reduced respiratory chain function, and increased amounts of a novel unprocessed RNA species (RNA 19). Overall effects on mitochondrial functions were more severe for the MELAS 3243 cybrids as compared to the MELAS 3271 cybrids. These data, combined with our previous observations, suggest that RNA 19 may play an important, but as yet uncharacterized, role in the pathogenesis of this mitochondrial disorder.

Assessment of the central dopaminergic index of plasma HVA in schizophrenia

Under fasting conditions, the dopamine (DA) metabolite homovanillic acid (HVA) in plasma originates mainly from central DA neurons or from central and peripheral noradrenergic (NA) neurons. The latter source contributes, in addition to HVA, the norepinephrine metabolites, for example, 3-methoxy-4-hydroxyphenylglycol (MHPG). It has been shown in primates that the association between HVA and MHPG in plasma or urine under varying rates of NA metabolism can be used to obtain an estimate of the central DA neuronal contribution of HVA to plasma or urine. This estimate is called the central dopaminergic index (CDI). Two studies presented here examine the applicability of this model in schizophrenia patients. The results were consistent with the proposed model and suggested that only about 30 percent of the total plasma HVA concentrations in our patients were derived from central DA neurons. A convenient modification of this model is proposed for future studies. Since the CDI of plasma HVA is not likely to be confounded by NA activity, this tool may prove useful in disentangling the roles played by the DA and NA systems in schizophrenia.

Memory functions in geriatric chronic schizophrenic patients: a neuropsychological study

This study characterized memory functions in geriatric schizophrenic inpatients with a battery of memory tests sensitive to neuropsychological impairments in either temporal or frontal brain regions. In patients clinically rated as cognitively impaired (n = 24), nearly all of these measures showed deficits relative to less impaired patients (n = 25). Factor analysis found consistent correlations between the tests and their putative cortical localization. Discriminant analysis suggested the pattern of impairments was not consistent with a generalized deficit. These results introduce the possibility, to be directly tested with neuropathological study, that the severe cognitive deficits in elderly schizophrenic patients are due to dysfunctions in either the temporal or frontal regions of the cerebral cortex, with the specific type of dysfunction varying across cases.

Early response to clozapine in schizophrenia

Forty schizophrenic patients were treated with clozapine for 5 weeks. Patients were then classified as treatment responders or nonresponders according to a priori established criteria. After only 1 week of treatment, the responders showed a significant decrease on the Brief Psychiatric Rating Scale (BPRS) total score and the psychosis and tension subscale scores. Higher BPRS scores at baseline and larger improvements in BPRS scores after the first week predicted a more favorable outcome in this trial and yielded good classification accuracy.

Immunogenicity of pneumococcal revaccination in patients with chronic disease

BACKGROUND

To prevent serious pneumococcal infections, 23-valent pneumococcal polysaccharide vaccine is recommended for individuals over 24 months of age with chronic predisposing diseases and for healthy older adults. This nonrandomized controlled study in rural Alaska assessed the immunogenicity of revaccination in adults.

METHODS

Twenty-six adults, 33 to 88 years of age, vaccinated a mean of 7.4 years before this study, were matched to 26 previously unvaccinated subjects by age, number of chronic diseases, sex, and ethnicity. One or more chronic diseases were validated in 62% of subjects (32 of 52). All received a first or second intramuscular dose of pneumococcal vaccine. Antibody levels were determined by radioimmunoassay for 12 pneumococcal capsular serotypes immediately before and 20 to 84 days after vaccination.

RESULTS

Six to 9 years after primary vaccination, over one third of serotype-specific antibody levels were below 500 ng of antibody nitrogen per milliliter, equal to the percentage in unvaccinated subjects of similar age. Antibody levels against all pneumococcal serotypes rose to similar levels after primary vaccination and revaccination, and 54% and 55%, respectively, of subjects who received primary vaccination and revaccination had at least a 1.4-fold increase in antibody levels. Only the antibody level for serotype 4 remained low. Neither gender nor age affected peak response. For those with chronic diseases, there was a trend toward fewer low antibody levels against three or more serotypes after revaccination (two subjects [13%]) than after primary vaccination (five subjects [31%]).

CONCLUSIONS

Following the initial immunization of high-risk and elderly patients with pneumococcal polysaccharide, pneumococcal antibody levels appear to wane with time. Primary vaccination and revaccination 6 or more years after a first dose of pneumococcal vaccine stimulate comparable mean antibody levels.

Adverse reactions in cattle to a capripox vaccine

Capripox vaccine (strain 0240) caused severe generalised skin reactions in vaccinated dairy cattle in two herds, whereas beef cattle did not develop reactions. All the reacting animals developed lumpy skin disease-like lesions. The incidence of skin lesions in first-lactation cows in herd A was 22.9 per cent and in herd B 29.3 per cent, mainly in the post-calving period. In older cows, the incidence was 10 per cent in herd A and 12.4 per cent in herd B. In herd B the high-yielding lactating cows were the most severely affected. There was a decrease of 3.5 per cent in milk production in each herd over a period of 12 days, and six first calving animals (3.5 per cent) and six cows (1.5 per cent) were slaughtered. A capripox virus was isolated from the animals with severe lesions, and was also demonstrated by electron microscopy. The histopathological lesions were similar to those of lumpy skin disease. The extent of the lesions appeared to be stress-related and, to a lesser degree, correlated with age and breed.

Effect of age on the immunogenicity of yeast recombinant hepatitis B vaccines containing surface antigen (S) or PreS2 + S antigens

A single-blind, multicenter, phase II trial of yeast recombinant hepatitis B virus (HBV) vaccines containing surface antigen (S) alone or with PreS2 (PreS2 + S) was conducted in 282 healthy HBV-seronegative adults aged 20-59 years. Each volunteer was randomly assigned to receive HBV vaccine containing 10 micrograms of S or one of three doses of PreS2 plus S: 2 + 10 micrograms, 4 + 20 micrograms, or 8 + 40 micrograms. The level of antibody to HBV surface antigen reached depended on the dose of S, not PreS2, received. In each vaccine group, volunteers 20-39 years old had higher titers of anti-PreS2 and antibody to S than those 40-59 years old. The age-related effect on immune response to HBV vaccination suggests that adults should be immunized against hepatitis B at as early an age as possible and that older persons may need a higher dose or booster immunizations to achieve durable immunity.

A pilot study of clonidine plus physostigmine in Alzheimer's disease

To assess the feasibility of one approach to combined cholinergic/noradrenergic treatment in Alzheimer's disease, ten patients were enrolled in a 2-week placebo-controlled study of oral physostigmine plus clonidine. The Alzheimer's Disease Assessment Scale (ADAS) was used as the primary outcome measure. Neither physostigmine alone, nor the combination of physostigmine plus clonidine, was associated with a statistically significant improvement for the group. Three patients did show an improvement of at least 4 points on the total ADAS score with the drug combination. The implications of these results for treatment strategies are discussed.

Serotype distribution and antimicrobial resistance patterns of invasive isolates of Streptococcus pneumoniae: Alaska 1986-1990

From January 1986 through December 1990, 672 cases of invasive pneumococcal disease were identified. From these, 574 pneumococcal isolates were recovered from normally sterile sites (blood, cerebrospinal and pleural fluid); 92% were serotypes represented in the 23-valent pneumococcal polysaccharide vaccine. The most common serotypes from children < 2 years old were 4, 6B, 9V, 14, 18C, 19F, and 23F, recovered from 83% of Alaska Native and 75.1% of nonnative children with invasive disease. Moderate penicillin resistance (MIC, 0.1-1.0 micrograms/mL) was found in 3.8% of isolates. All were sensitive to chloramphenicol, vancomycin, rifampin, ceftriaxone, cefotaxime, cephalothin, and cefaclor. However, in the Yukon-Kuskokwim Delta region, 16.9% of isolates were moderately resistant to penicillin, and 10.8% were resistant to erythromycin and 6.2% to trimethoprim-sulfamethoxazole; the number resistant to two or more antibiotics increased significantly during surveillance. All multiply resistant isolates were serotype 6B, and all were from Alaska Native patients < 2 years old.

The epidemiology of invasive pneumococcal disease in Alaska, 1986-1990--ethnic differences and opportunities for prevention

To assess prevention strategies for pneumococcal disease in Alaska, prospective surveillance during 1986-1990 identified 672 invasive pneumococcal infections, including 315 among Alaska Natives. Age-adjusted annual incidence was 74 per 100,000 for Alaska Natives and 16 per 100,000 for nonnatives. The annual incidence in Alaska Native children < 2 years old was 624 per 100,000; rates of 84 per 100,000 for meningitis and 290 per 100,000 for bacteremic pneumonia were 8-10 times higher than for other US groups. By age 75, cumulative incidence (7%) and mortality (1%) in Alaska Natives were almost 4 times higher than for nonnatives. Only 17% of Alaska Native adults with predisposing conditions and invasive infections previously received pneumococcal vaccine. For Alaska Natives, a proposed heptavalent conjugate pneumococcal vaccine will include serotypes responsible for 85% of invasive isolates from children < 2 years but only 32% of those from adults. The 23-valent polysaccharide pneumococcal vaccine, which contains > 94% of serotypes identified in Alaska Native toddlers and adults, should be used more widely.

Attentional predictors of clinical change during neuroleptic treatment in schizophrenia

Improvement in auditory selective attention performance was examined in acute schizophrenic inpatients (n = 13) both off and on medication using the digit span distraction task. Subjects were tested at drug-free baseline and weekly for three weeks during treatment with haloperidol. Improvements in distractability preceded and predicted clinical improvements. A control group of stable schizophrenic outpatients (n = 12) medicated at all testing intervals were examined during the same time period. No significant clinical or attentional changes were found in the control group over the four testing intervals. These results suggest that specific types of attentional functions are intrinsically related to the biological processes affected by neuroleptic treatment and lend preliminary support to the contention that schizophrenic symptoms are mediated by attentional impairment.

Clozapine treatment and its effect on neuroendocrine responses induced by the serotonin agonist, m-chlorophenylpiperazine

The effects of clozapine treatment on neuroendocrine responses induced by the serotonin agonist, m-chlorophenylpiperazine (mCPP) were examined. mCPP and placebo were administered after a 2-week drug-free period and again after 5 weeks of clozapine treatment in nine schizophrenic inpatients. Adrenocorticotropic hormone (ACTH), prolactin, and mCPP levels were measured. Clozapine treatment completely blocked mCPP-induced ACTH and prolactin release suggesting that clozapine blocks serotonin receptors that mediate these hormone responses.

Characterization of cadherin-4 and cadherin-5 reveals new aspects of cadherins

Several properties of cadherin-4 and cadherin-5 were characterized by using the cDNA transfection approach. The proteins of both cadherins had a relative molecular mass of about 130 kDa and were present at the cell periphery, especially at cell-cell contact sites. These cadherins were easily digested with trypsin, and Ca2+ protected cadherin-4, but not cadherin-5, from the digestion. In immunoprecipitation, cadherin-4 co-precipitated with two major proteins of 105 kDa and 95 kDa, respectively. The 105 kDa and the 95 kDa proteins are likely to correspond to alpha- and beta-catenins. Cadherin-5 co-precipitated with only one major protein of 95 kDa, but seems to associate with the 105 kDa protein. On the other hand, plakoglobin or gamma-catenin did not co-precipitate well with either cadherin-4 or cadherin-5 in immunoprecipitation, but plakoglobin also appears to associated weakly with these cadherins. Cadherin-4 transfectants aggregated within 30 minutes in a cell aggregation assay, but cadherin-5 transfectants did not aggregate under the same conditions. Furthermore, the transfectants of chimeric cadherin-4 with cadherin-5 cytoplasmic domain showed cell aggregation activity comparable to that of wild-type cadherin-4 transfectants, whereas the transfectants of chimeric cadherin-5 with cadherin-4 cytoplasmic domain did not show appreciable cell aggregation, suggesting that the extracellular domains of cadherins, in conjunction with their cytoplasmic domains, play an important role in cell aggregation activity. These results show that cadherin-4 is very similar to the classical cadherins, whereas cadherin-5 is functionally as well as structurally distinct from classical cadherins.

Cortical cholinergic markers in schizophrenia

Cortical cholinergic deficits have been implicated in the cognitive deficits produced by a variety of neurodegenerative diseases including Alzheimer's disease (AD). Recent studies have suggested that many of the chronically institutionalized geriatric schizophrenic patients are also cognitively impaired. In this postmortem study we compared cholinergic marker activity in six different cortical regions derived from elderly controls, chronically institutionalized geriatric schizophrenic patients, and AD patients. All of the Alzheimer's disease cases met neuropathological criteria for AD, while none of the schizophrenic cases met criteria for AD. Cholinergic marker activity (choline acetyltransferase and acetylcholinesterase) was significantly diminished in the AD cohort but not in the schizophrenic cohort. Additionally, cortical choline acetyltransferase activity was significantly and negatively correlated with Clinical Dementia Rating scores (CDR), whereas no such correlations were evident in the schizophrenic cohort. These results suggest that cognitive deficits in geriatric schizophrenics are not due to diminished cortical cholinergic activity.